After a little searching here, I did find a few mentions of audio sync issues with Magix's Prores renders going back to V14. I just finished rendering an old project to Prores in V15, just to see if it would complete, which it did, but the audio is WAY out of sync. The edit has several audio tracks and I did read that more complex audio and long projects would cause this. I guess it still does. I have done a few simple Prores renders with no problems but there still seems to be an audio sync issue with long projects.